Preface:

This is the eleventh edition of CSA C22.3 No. 1, Overhead systems, one of a series of Standards issued under the Canadian Electrical Code, Part III. It supersedes the previous editions, published in 2015, 2010, 2006, 2001, 1987, 1985, 1979, 1976, and 1970, and the original edition, which was published as a series of five Standards in 1959, 1953, 1947, and 1940.

Major changes to this edition include the following:
a) a revised scope of the Standard extends to the inside of buildings or sections of buildings that are employed by a utility;
b) new and revised definitions with an updated use of terminology:
     i) the following new definitions: "buckling", "covered conductor bundled system", "geometric non-linearity", "minor waterways", "stability", and "wireless communication antenna"; and
     ii) the following revised definitions: "linear analysis", "non-linear analysis", and "service conductor";
c) revision to Clause 4.1.3 on accessibility;
d) revision to Clause 4.2.7.2 on the use of guy insulators;
e) new clauses added to address
     i) wireless communication antenna; and
     ii) natural gas and propane equipment clearances and separations;
f) revision to Clauses 5.2.5 and 5.2.6 on conductor temperature for thermal loading conditions;
g) revision to weather loading methods in Clause 7.2.3 to include historical weather loads;
h) climate change adaptation requirements to neutral supported secondary service wires;
i) the requirements on structural analysis (geometric non-linear design);
j) conductor tension considerations under structure deflection to improve clarity;
k) effective grounding requirements of non-current-carrying items under Clauses 9.1.8 and 9.2.7;
l) minimum vertical design clearances and separations above ground or rails in Tables 2 and 4 and Figure A.14;
m) Table 9 for minimum clearances to above-ground pipelines;
n) Table 10 for minimum design clearances to bridges;
o) minimum design vertical clearances between wires crossing each other and supported by different supporting structures: Table 13 to expand on the clearances between ac (upper level) and dc (lower level)
p) Table 35 for flashover distance for ac conductors and Table 36 for dc conductors;
q) Annex A:
     i) guidance on the use of prior versions of this Standard;
     ii) guidance on the point of attachment for supply conductors to buildings; and
     iii) guidance on information criteria to replace or reinforce wood pole structures;
r) Annex D: Table D.1, mean annual maximum snow depth for selected Canadian locations; and
s) Annex E for guidance on the covered conductor bundled systems.

CSA Group acknowledges that the development of this Standard was made possible, in part, by the financial support of the Canadian Electricity Association (CEA), Schneider Electric Canada Inc., IFD Corporation, Hydro Québec, S&C Electric Canada Ltd., Fortis Alberta, Fortis BC, Maritime Electric, Newfoundland Hydro, Newfoundland Power, EPCOR, Utilities Standards Forum (USF), and Alectra Utilities.

This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group.

Scope:

1.1
This Standard applies to electric supply and communication lines and equipment located entirely outside of buildings and fenced supply stations and buildings, and also where the installations or equipment are inside buildings or sections of buildings where they are employed by a utility of
a) an electric system;
b) a communication system; or
c) a community antenna distribution system in the exercise of its function as a utility.

1.2
Existing installations meeting the requirements of prior editions of this Standard need not be modified to comply with this edition of the Standard, except as might be required for safety reasons by the authority having jurisdiction.

1.3
This Standard, which forms part of the Canadian Electrical Code, Part III, provides requirements for the construction of overhead systems. It covers electric supply and communication circuits that
a) are installed alone;
b) are in joint-use;
c) are in proximity to each other or other facilities;
d) cross each other or other facilities; and
e) cross railways, highways, navigable waterways, or land that is likely to be traversed by vehicles or pedestrians.

1.4
This Standard presents a choice between deterministic and reliability-based design methods. Reliability based design methods are covered by CSA C22.3 No. 60826.

1.5
The requirements contained in this Standard do not constitute complete design and construction specifications, but rather prescribe the minimum design requirements that are most important to the
a) safety of persons;
b) continuity of service; and
c) protection of property.

1.6
Conditions not covered by this Standard are governed by equivalent Standards in common use or by the authority having jurisdiction.

1.7
In some cases in this Standard, specific types of construction are envisaged. This does not preclude the use of other types of construction, provided that the engineering representatives involved can demonstrate the safety and suitability of these alternatives.

1.8
The use of terms such as "where practicable" is not intended to provide an opportunity for not meeting the requirements of this Standard, but indicates the preferred clearance or method. Where an alternative is not specified, the engineering solution that most closely adheres to the preferred method should be used.

1.9
Where the requirements of more than one clause apply, all should be satisfied.

1.10
In this Standard, "shall" is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; "should" is used to express a recommendation or that which is advised but not required; and "may" is used to express an option or that which is permissible within the limits of the Standard. Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material. Notes to tables and figures are considered part of the table or figure and may be written as requirements. Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.